1. Field of the Invention
This invention relates to the combined use of an acidulant system and a buffer salt system to increase the stability of lemon/lime flavored beverages. This invention further relates to lemon/lime flavored beverages which include such acidulant and buffer salt systems.
2. Related Background Art
Lemon/lime flavored beverages are very popular throughout the world. Such beverages may be carbonated or non-carbonated and may or may not contain juice. For example, 7-Up® is a well known lemon/lime flavored carbonated soft drink. In addition, lemon/lime flavored cola beverages are currently very fashionable. Further, other types of lemon/lime flavored beverages such as sports drinks are enjoyed on a worldwide basis.
Conventionally, lemon/lime flavored beverages are formulated to a relatively low pH in order to produce a desired level of tartness or sourness, a taste attribute which is key for lemon/lime flavored beverages. However, at such a low pH, lemon/lime flavor is not stable for extended periods of time. In fact, key ingredients of lemon/lime flavor degrade under such acidic conditions, thereby causing diminished flavor and off-tastes.
Lemon/lime flavor does become more stable at higher pHs, Freeburg, et al., Perfumer & Flavorist, vol. 19, pp. 23-32 (1994), and it is within the skill of one of ordinary skill in this art to raise the pH of a beverage formulation by increasing buffering salts and/or reducing acids. Unfortunately though, at higher pH levels, the perception of tartness or sourness of a beverage is unacceptably compromised. Hence, it is difficult to produce a lemon/lime flavored beverage with a good shelf life.
In addition to the problems associated with shelf life, the instability of lemon/lime flavor at lower pHs limits the applications to which lemon/lime flavor can be applied. For example, cola beverages are typically formulated to a pH of about 2.5 to 2.8 using two acidulants, namely phosphoric acid and citric acid, and sodium or potassium citrate as a buffering salt. Due to the low pH, it is not possible to make a good tasting, storage-stable lemon/lime flavored cola drink by simply adding lemon/lime flavor to such a conventionally formulated cola drink since the lemon/lime flavor will degrade and compromise the overall flavor of the cola.
U.S. Pat. No. 5,348,756 addresses a similar problem regarding gelatin gels. Therein, a higher pH was desirable in terms of reducing the gelatin load necessary to obtain a desired gel strength, yet a higher pH typically reduced the desired sour taste and/or produced off-tastes. According to U.S. Pat. No. 5,348,756, a combination of (1) adipic acid, (2) fumaric acid and/or citric acid, (3) phosphate salts and (4) citrate salts was used to formulate a gelatin gel having a pH of about 4.15 to 4.5 which exhibited a desired gel strength and taste and which required a lower gelatin load. U.S. Pat. No. 5,348,756 relates to gelatin gels and powdered mixes therefor only.
Hence, there exists a dilemma in the formulation of lemon/lime flavored beverages. There are competing interests (1) to raise the pH significantly to improve the stability of lemon/lime flavor and (2) to maintain or increase the tartness perception commonly associated with the lemon/lime flavor. In short, there is a need for good tasting, storage-stable lemon/lime flavored beverages.